library(ggplot2)
ggplot(data1,aes(x, weight=count)) + geom_histogram(binwidth=1) + xlim(0,400) + ggtitle(“title”)
Tag Archives: Data Mining
KB: Using DBSCAN in R with precomputed distance
File “points.txt” contains the X, Y coordinates of the points. We want to customize the distance calculation and feed into DBSCAN as a distance object.
Data file – points.txt
x y 5 8 6 7 6 5 2 4 3 4 5 4 7 4 9 4 3 3 8 2 7 5
R Script
library(dbscan)
data=read.table("d:/temp/points.txt", sep="\t", header=TRUE)
distance=matrix(,nrow=nrow(data),ncol=nrow(data))
for(i in 1:nrow(data)){
for(j in i:nrow(data)){
dx=abs(data$x[i]-data$x[j])^0.5
dy=abs(data$y[i]-data$y[j])^0.5
distance[i,j]=(dx+dy)^2
distance[j,i]=(dx+dy)^2
}
}
result=dbscan(as.dist(distance), eps=4, minPts=3)
result$cluster
Visualizing DBSCAN Clustering
HOWTO: Basic data processing in R
Reading CSV data without header
MyData = read.csv(“D:/temp/iris.txt”,header=FALSE)
colnames(MyData) <- c(“col1″,”col2″,”col3″,”col4”)
Reading Tab-delimited data without header
MyData = read.table(“D:/temp/iris.txt”,sep=”\t”,header=FALSE)
colnames(MyData) <- c(“col1″,”col2″,”col3″,”col4”)
Viewing table
View(MyData)
Removing column from table
MyData$col4<-NULL
List memory content
ls()
Remove data
rm(MyData)
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